The Signature Decay Method (found under Account Settings / Profile) identifies the algorithm that will be used to model the detraining effects that occur between your activities. For example, if you go four weeks without training, the Fitness Signature you have now will not be the same as what it was four weeks ago.

Xert will model this decline in fitness signature, i.e. a decay, after each activity. If you train on a regular basis, this decay will not be apparent. But if you stop or decrease down your training, there will be an affect on your fitness.

There are 4 options when selecting a decay method:

Decay Method Description
No Decay – Training Load Matched The No Decay method can be used during periods where you are training but not performing any maximal efforts, AND you wish to have the system track your increases & decreases in fitness signature more precisely over this period. Using this method will tell the system to increase/decrease your signature parameters as your training load increases/decreases.

WARNING: If you use this decay method over longer periods, particularly if anomalies exist in your data (even subtle ones), your fitness signature may end up being higher than what you can achieve and you will no longer be able to obtain a fitness breakthrough. If you are using this setting and haven’t seen a breakthrough in a while despite many efforts, you may want to choose another decay method.

Small Decay This decay method falls in between Optimal and No Decay and can be used to fine tune your signature to reduce the impact of a decay, for training purposes.
Optimal Decay – Default This is the default decay method used by the system. It will follow your breakthroughs and your training loads as they move up and down. It has an additional decay that will still express your fitness in cases where your signature numbers have inadvertently become too high. This ensures that your progression data stays accurate and provides opportunities for breakthroughs to validate your progress.

Optimal Decay can be used during all phases of your Training Program, but it is most effective during Build and Peak phases when fitness breakthroughs are more frequently.  No Decay is preferred during the Base phase in general.

Aggressive Decay This decay method will trigger more breakthroughs and variation in your progression to help identify potential decreases or increases that may be missed when using the other methods.